Case IH 3703 (DTC 2B36) - ECU – Engine Control Unit (ECU): The minimum rail pressure value necessary to allow fuel injection has not been reached.

The engine control system has detected that the fuel pressure inside the high-pressure common rail is too low to safely or effectively initiate fuel injection. Because the minimum pressure threshold is not met, the engine will fail to start, stall, or enter a severe derate/shutdown mode to protect the fuel system components.

• MAXXUM T4E
• 240 Series Axial-Flow (7240, 8240, 9240)
• 230 Series Axial-Flow (7230, 8230, 9230)
• Magnum
• Steiger
• Puma
• Maxxum
• Farmall

1. 1

   Verify there is adequate fuel in the tank and that it is not gelled or heavily contaminated with water

2. 2

   Inspect the low-pressure fuel lines from the tank to the lift pump for kinks, collapsed hoses, or air leaks

3. 3

   Check the primary (water separator) and secondary fuel filters for severe clogging

4. 4

   Verify the low-pressure electric or mechanical lift pump is supplying adequate pressure to the high-pressure pump

5. 5

   Connect the diagnostic tool and monitor Actual Rail Pressure versus Desired Rail Pressure during engine cranking

6. 6

   Inspect the wiring harness and connectors at the Fuel Rail Pressure Sensor and the Fuel Metering Unit (M-Prop) for chafing, corrosion, or loose pins

1. 1

   Replace Fuel Filters & Prime

   Drain and replace both the primary and secondary fuel filters. Bleed/prime the fuel system to ensure absolutely no air is trapped in the low-pressure side. Clear the fault code and attempt to start the engine.

2. 2

   Test the Fuel Pressure Relief Valve (PRV)

   Disconnect the return line from the PRV. Crank the engine. If any fuel flows out of the relief valve during cranking, the valve is stuck open or has failed mechanically and must be replaced.

3. 3

   Test the Fuel Rail Pressure Sensor

   If the EST shows erratic pressure readings, or shows high pressure when the engine is completely off, the sensor has failed. Disconnect the harness, remove the sensor from the rail, and install a new sensor. Torque to OEM specifications.

4. 4

   Inspect the Fuel Metering Unit

   Check its resistance. If it is stuck closed or electrically failed, replace the metering unit.

5. 5

   Injector Leak-Off Test

   If the sensors and valves are good, one or more fuel injectors may have excessive internal bypass leakage, preventing the rail from building pressure. Perform an injector return flow (leak-off) test. Replace any injectors that exceed the maximum return volume.

6. 6

   High-Pressure Pump Replacement

   If all low-pressure supply is good, no injectors are leaking, the PRV is holding, and the metering unit is functional, the high-pressure CP3/CP4 fuel pump has failed internally and must be replaced.